823 research outputs found
Negative pressure wound therapy for soft tissue injuries around the foot and ankle
<p>Abstract</p> <p>Background</p> <p>This study was performed to evaluate the results of negative pressure wound therapy (NPWT) in patients with open wounds in the foot and ankle region.</p> <p>Materials and methods</p> <p>Using a NPWT device, 16 patients were prospectively treated for soft tissue injuries around the foot and ankle. Mean patient age was 32.8 years (range, 3–67 years). All patients had suffered an acute trauma, due to a traffic accident, a fall, or a crush injury, and all had wounds with underlying tendon or bone exposure. Necrotic tissues were debrided before applying NPWT. Dressings were changed every 3 or 4 days and treatment was continued for 18.4 days on average (range, 11–29 days).</p> <p>Results</p> <p>Exposed tendons and bone were successfully covered with healthy granulation tissue in all cases except one. The sizes of soft tissue defects reduced from 56.4 cm<sup>2 </sup>to 42.9 cm<sup>2 </sup>after NPWT (mean decrease of 24%). In 15 of the 16 cases, coverage with granulation tissue was achieved and followed by a skin graft. A free flap was needed to cover exposed bone and tendon in one case. No major complication occurred that was directly attributable to treatment. In terms of minor complications, two patients suffered scar contracture of grafted skin.</p> <p>Conclusion</p> <p>NPWT was found to facilitate the rapid formation of healthy granulation tissue on open wounds in the foot and ankle region, and thus, to shorten healing time and minimize secondary soft tissue defect coverage procedures.</p
Acupuncture Induced Necrotizing Aortitis with Infected Pseudoaneurysm Formation
Necrotizing aortitis is a rare and life-threatening complication of local or generalized bacterial infections and most commonly affects the abdominal aorta. We described a case of a 79-year-old man with an acupuncture-induced bacterial aortitis associated with pseudoaneurysm formation causing near rupture. The patient underwent emergent explolapartomy, resection of the infected aorta, wide debridement of surrounding infected tissues, and extra-anatomic axillary to bifemoral graft bypass. The microbiologic examination revealed Escherichia coli and methicillin resistant Staphylococcus aureus (MRSA). Necrotizing aortitis is very serious and fatal disease, careful history taking as well as rapid diagnosis and urgent treatment are of critical importance
Understanding the accelerator from resources-based perspective
Purpose - This study aims to explore Accelerators and their practices in sustaining start-ups within their innovative programs for these companies based on the resource-based perspective. Moreover, with an ever-increasing demand for Accelerators amongst start-up companies, this study also demonstrates the importance of Accelerators, as it pertains to new venture creation. Design/methodology/approach - This research uses an exploratory case study approach to examine a comparative view of leading Accelerator companies in the USA and Korea based on resource support. Findings - The results of this study show that there are a number of differences between Accelerators of the two countries in terms of the resources they support for early-stage start-ups. The findings also show some similarities. However, in Korea, the Accelerator landscape is limited, where mentorship, resources and investments are not readily accessible, resulting in low success rates for Korean start-up companies. These limitations have had a negative trickle-down effect when providing entrepreneurs with strong access to resources and investors, which highly affects the success rates of early-stage start-ups. Practical implications - In terms of the resource-based theory, this study contributes to the growth of early start-ups by emphasizing the role of the accelerator and suggesting the extent and impact that entrepreneurs have access to resources and investors. Originality/value - With significant growth in start-ups around the world, the necessity for start-up funding and mentorship has increased drastically. Start-up companies need various types of assets, systems, knowledge and information to achieve their goals. In Accelerators, start-ups receive all the aforementioned resources while also improving their entrepreneurial skills. Start-up companies have many options in seeking investors who support both tangible and intangible resources to boost growth. While there is a wealth of information on traditional funding methods, there are few studies that shed light on the role of Accelerators from the resource-based point of view
The Usefulness of New-Generation Capsule Endoscopy in Patients with Portal Hypertensive Enteropathy
Excessive Exercise Habits in Marathoners as Novel Indicators of Masked Hypertension
Background. Excessive exercise such as marathon running increases the risk of cardiovascular events that may be related to myocardial infarction and sudden death. We aimed to investigate that the exercise characteristics can be used as a novel indicator of masked hypertension. Methods. A total of 571 middle-aged recreational male marathoners were assigned to a high blood pressure group (HBPG; = 214) or a normal blood pressure group (NBPG; = 357). A graded exercise test was used to examine the hemodynamic response and cardiac events, and the personal exercise characteristics were recorded. Results. Systolic blood pressure and diastolic blood pressure were higher in the HBPG than in the NBPG ( < 0.05, all). The marathon history, exercise intensity, and time were longer and higher, whereas the marathon completion duration was shorter in the HBPG than in NBPG ( < 0.05, all). HBPG showed a higher frequency of alcohol consumption than NBPG ( < 0.05). Conclusion. More excessive exercise characteristics than the normative individuals. If the individuals exhibit high blood pressure during rest as well as exercise, the exercise characteristics could be used as a novel indicator for masked hypertension
Dissociation of Progressive Dopaminergic Neuronal Death and Behavioral Impairments by Bax Deletion in a Mouse Model of Parkinson's Diseases
Parkinson's disease (PD) is a common, late-onset movement disorder with selective degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Although the neurotoxin 6-hydroxydopamine (6-OHDA) has been used to induce progressive degeneration of DA neurons in various animal models of PD, the precise molecular pathway and the impact of anti-apoptotic treatment on this neurodegeneration are less understood. Following a striatal injection of 6-OHDA, we observed atrophy and progressive death of DA neurons in wild-type mice. These degenerating DA neurons never exhibited signs of apoptosis (i.e., caspase-3 activation and cytoplasmic release of cytochrome C), but rather show nuclear translocation of apoptosis-inducing factor (AIF), a hallmark of regulated necrosis. However, mice with genetic deletion of the proapoptotic gene Bax (Bax-KO) exhibited a complete absence of 6-OHDA-induced DA neuron death and nuclear translocation of AIF, indicating that 6-OHDA-induced DA neuronal death is mediated by Bax-dependent AIF activation. On the other hand, DA neurons that survived in Bax-KO mice exhibited marked neuronal atrophy, without significant improvement of PD-related behavioral deficits. These findings suggest that anti-apoptotic therapy may not be sufficient for PD treatment, and the prevention of Bax-independent neuronal atrophy may be an important therapeutic target
Synergistic effect of Indium and Gallium co-doping on growth behavior and physical properties of hydrothermally grown ZnO nanorods
We synthesized ZnO nanorods (NRs) using simple hydrothermal method, with the simultaneous incorporation of gallium (Ga) and indium (In), in addition, investigated the co-doping effect on the morphology, microstructure, electronic structure, and electrical/optical properties. The growth behavior of the doped NRs was affected by the nuclei density and polarity of the (001) plane. The c-axis parameter of the co-doped NRs was similar to that of undoped NRs due to the compensated lattice distortion caused by the presence of dopants that are both larger (In3+) and smaller (Ga3+) than the host Zn2+ cations. Red shifts in the ultraviolet emission peaks were observed in all doped NRs, owing to the combined effects of NR size, band gap renormalization, and the presence of stacking faults created by the dopant-induced lattice distortions. In addition, the NR/p-GaN diodes using co-doped NRs exhibited superior electrical conductivity compared to the other specimens due to the increase in the charge carrier density of NRs and the relatively large effective contact area of (001) planes. The simultaneous doping of In and Ga is therefore anticipated to provide a broader range of optical, physical, and electrical properties of ZnO NRs for a variety of opto-electronic applications
Multiobjective loading pattern optimization by simulated annealing employing discontinuous penalty function and screening technique
The problem of multiobjective fuel loading pattern (LP) optimization employing high-fidelity
three-dimensional (3-D) models is resolved by introducing the concepts of discontinuous penalty function,
dominance, and two-dimensional (2-D)–based screening into the simulated annealing (SA) algorithm.
Each constraint and objective imposed on a reload LP design is transformed into a discontinuous penalty
function that involves a jump to a quadratic variation at the point of the limiting value of the corresponding
core characteristics parameter. It is shown that with this discontinuous form the sensitivity of the
penalty coefficients is quite weak compared to the stochastic effect of SA. The feasible LPs found during SA
update the set of candidate LPs through a dominance check that is done by examining multiple objectives
altogether. The 2-D–based screening technique uses a precalculated database of the 2-D solution errors
and is shown to be very effective in saving the SA computation time by avoiding 3-D evaluations for the
unfavorable LPs that are frequently encountered in SA. Realistic applications of the proposed method to a
pressurized water reactor reload LP optimization with the dual objectives of maximizing the cycle length
and minimizing the radial peaking factor demonstrate that the method works quite well in practice.This work was supported by the project funded by the Ministry of Knowledge Economy of Korea to develop primary design codes for nuclear power plants
Adsorptive removal of CO2 from CO2-CH4 mixture using cation-exchanged zeolites
Raw natural gas and landfill gas contains methane as its major component, but it also contains considerable amounts of contaminants such as CO2 and H2S (i.e. acid gases) that can cause corrosion and fouling of the pipeline and equipment during transportation and liquefaction. Amine-based CO2 gas removal processes have been employed in the gas industry, but these processes have disadvantages including high regeneration energy requirements and inefficiencies; these issues have not been adequately solved to date. Currently, adsorptive acid gas removal technologies have received significant interest because of the simplicity of adsorbent regeneration by thermal or pressure variation1). Numerous micro- and mesoporous adsorbents including zeolites [2-3], titanosilicates[4], activated carbons[5-6], metal-organic-framework (MOF) [7], and silica-alumina materials[8-9] were studied for this type of application. However, the CO2/CH4 selectivity of the aforementioned adsorbents was not high enough for commercial applications.In this study, different cation-exchanged zeolites were synthesized, physicochemically characterized, and evaluated for adsorptive removal of CO2 from CO2-CH4 mixtures. The adsorption isotherms of CO2 and CH4 in the pressure and temperature ranges 0 − 3MPa and 10 – 40 oC, respectively, for different cation-exchanged zeolites were measured and compared. The ideal-adsorbed solution theory (IAST) was employed for the estimation of CO2/CH4 selectivity for the different cation-exchanged zeolites.
References
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3) M. W. Seery, US Patent No. 5,938,819. 1999
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Prevention of mitochondrial impairment by inhibition of protein phosphatase 1 activity in amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease caused by progressive loss of motor neurons (MNs) and subsequent muscle weakness. These pathological features are associated with numerous cellular changes, including alteration in mitochondrial morphology and function. However, the molecular mechanisms associating mitochondrial structure with ALS pathology are poorly understood. In this study, we found that Dynamin-related protein 1 (Drp1) was dephosphorylated in several ALS models, including those with SOD1 and TDP-43 mutations, and the dephosphorylation was mediated by the pathological induction of protein phosphatase 1 (PP1) activity in these models. Suppression of the PP1-Drp1 cascade effectively prevented ALS-related symptoms, including mitochondrial fragmentation, mitochondrial complex I impairment, axonal degeneration, and cell death, in primary neuronal culture models, iPSC-derived human MNs, and zebrafish models in vivo. These results suggest that modulation of PP1-Drp1 activity may be a therapeutic target for multiple pathological features of ALS
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